Meet Your Digital Butler: a 'Social OS'

What if all of us had our own search engine for everyone with whom we have ever come in contact, no matter how trivial our interaction? And what if it already knew who they were, and served as a master contacts database for pretty much the entire world? And what if this service lived on all our devices, organizing the world according to people rather than places or things? In the car, you would tell it who you plan to meet. On your wrist, it's a way to never forget a name. On your phone, well, it's your phone.